This section provides background information related to the present disclosure which is not necessarily prior art.
An assembly of this kind may be a transfer case, for example, that allows a direct distribution of a driving torque between two wheels of an axle of the motor vehicle and/or—with an all-wheel drive vehicle—a direct distribution of the driving torque between a front axle and a rear axle of the motor vehicle.
Such assemblies have to be controlled with high accuracy to be able to carry out the distribution of the driving torque with the required precision. However, hardly avoidable tolerances occur in their manufacture that result in deviations in the response behavior of the assemblies. These deviations are determined individually for the purpose of a calibration, with a respective tolerance class being associated with the assemblies in accordance with a predetermined classification scheme. The respectively determined tolerance class of a specific assembly may be taken into account by the associated control unit of the vehicle to control the assembly with the desired precision.
There is a problem in connection with a classification of controllable assemblies—whether in automotive engineering or in other fields—in that the respective assembly and the control unit associated therewith are sometimes installed independently of one another. A teach-in process therefore usually takes place after the installation of the assembly and the control unit in which the respective then current classification of the assembly used is communicated to the control unit and is stored in it. If a replacement or repair of the assembly and/or of the control unit takes place later, for example in case of service, the teach-in process has to be carried out again so that the correct control of the assembly by the control unit is in turn ensured.
It has already been proposed to encode the classification of an assembly with the help of an additional coding plug. DE 103 33 651 A1, for example, describes a coding plug that can be connected directly or indirectly to a control unit and which has a fixed electric circuit. A defined electrical state may be generated by the fixed circuit in the control unit and the state is detected and compared with stored data. The electrical state is then associated with a tolerance class of the assembly that may in turn be used for the adaptation of maps/characteristics for the control of the assembly.
It is, however, disadvantageous with this solution that an additional failure risk of the controllable assembly arises due to the coding plug made as an additional component. Furthermore, the reading out, decoding and comparing of the classification information stored in the circuit of the coding plug may only be realized in a relatively complex and/or expensive manner. In addition, the coding plug likewise has to be replaced on a change of the tolerance class of the assembly. Ultimately, it thus cannot be precluded that a coding plug is connected to the controllable assembly that contains an incorrect classification so that the classification read out of the coding plug by the control unit does not reflect the correct tolerance class of the assembly. The control of the assembly is thereby even made worse under certain circumstances—in comparison with a control solution without any consideration of the tolerance class.